/*
 *	Generate the syscall functions
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "syscall_name.h"

static char namebuf[128];

static void write_call(int n)
{
  int args;
  FILE *fp;
  snprintf(namebuf, 128, "fuzixpdp11/syscall_%s.s", syscall_name[n]);
  fp = fopen(namebuf, "w");
  if (fp == NULL) {
    perror(namebuf);
    exit(1);
  }
  fprintf(fp, "\t.text\n\t.even\n\n"
	      "\t.globl _%1$s\n\n"
	      "_%1$s:\n", syscall_name[n]);
  /* All current varargs max at 3 */
  if (syscall_args[n] == VARARGS)
    args = 3;
  else
    args = syscall_args[n];

  /* FIXME: save r2/r3 if needed */
  switch(n) {
    case 2:
      fprintf(fp, "\tmov 4(sp),r1\n");
    case 1:
      fprintf(fp, "\tmov 2(sp),r0\n");
    case 0:
      break;
    case 3:
      fprintf(fp, "\tmov r2,-(sp)\n\tmov 4(sp),r0\n"
                  "\tmov 6(sp),r1\n\tmov 8(sp),r2\n");
      break;
    case 4:
      fprintf(fp, "\tmov r2,-(sp)\n\tmov r3,-(sp)\n"
                  "\tmov 6(sp),r0\n\tmov 8(sp),r1\n"
                  "\tmov 10(sp),r0\n\tmov 12(sp),r1\n");
      break;
  }
  fprintf(fp, "\ttrap $%d\n", n);
  fprintf(fp, "\ttst r1\n\tbeq noerr\n");
  fprintf(fp, "\tmov r1,_errno\n");
  fprintf(fp, "\tnoerr:\n");
  switch(n) {
    case 3:
      fprintf(fp, "\tmov (sp)+, r3\n");
    case 2:
      fprintf(fp, "\tmov (sp)+, r2\n");
  }
  fprintf(fp, "\trts pc\n");	/* And restore R2/R3 if needed */
  fclose(fp);
}

static void write_call_table(void)
{
  int i;
  for (i = 0; i < NR_SYSCALL; i++)
    write_call(i);
}

static void write_makefile(void)
{
  int i;
  FILE *fp = fopen("fuzixpdp11/Makefile", "w");
  if (fp == NULL) {
    perror("Makefile");
    exit(1);
  }
  fprintf(fp, "# Autogenerated by tools/syscall_pdp11\n");
  fprintf(fp, "CROSS_AS=pdp11-aout-as\nCROSS_LD=pdp11-aout-ld\nCROSS_AR=pdp11-aout-ar\n");
  fprintf(fp, "ASOPTS=\n\n");
  fprintf(fp, "ASRCS = syscall_%s.s\n", syscall_name[0]);
  for (i = 1; i < NR_SYSCALL; i++)
    fprintf(fp, "ASRCS += syscall_%s.s\n", syscall_name[i]);
  fprintf(fp, "\n\nASRCALL = $(ASRCS)\n");
  fprintf(fp, "\nAOBJS = $(ASRCALL:.s=.o)\n\n");
  fprintf(fp, "syslib.lib: $(AOBJS)\n");
  fprintf(fp, "\techo $(AOBJS) >syslib.l\n");
  fprintf(fp, "\t$(CROSS_AR) rc syslib.lib $(AOBJS)\n\n");
  fprintf(fp, "$(AOBJS): %%.o: %%.s\n");
  fprintf(fp, "\t$(CROSS_AS) $(ASOPTS) -o $*.o $<\n\n");
  fprintf(fp, "clean:\n");
  fprintf(fp, "\trm -f $(AOBJS) $(ASRCS) syslib.lib syslib.l *~\n\n");
  fclose(fp);
}

int main(int argc, char *argv[])
{
  write_makefile();
  write_call_table();
  exit(0);
}
